Improvement in key-fasteners



13-3. DOPP & L. 0. WALTERS. Key-Fastener.

No. 212,543. Patented Feb. 25, I879.

Fiyi' flizesz: OHS;

N,PETER5. PHOTO-LYHOGRAPNER WASHINGTON D c UNITED STATES -PATENT OFFICE.

DANIEL E. DOPP, OF VVHEELING, AND LOUIS O. WALTERS, OF BARRINGTON,ILLINOIS.

IM PROVEMENT IN KEY-FASTENERS.

Specificationforming part of Letters Patent No. 212,543, dated February25, 1879; application filed December 23, 1878.

To allwhom it may concern Be it known that we, DANIEL E. DoPP, ofWheeling, and LOUIS (J. WALTERS, of Barrington, both in the county ofCook and State of Illinois, have invented a new and Improved SafetyAttachment for Locks; and we hereby declare the following to be a full,clear, and exact description thereof, reference being had to theaccompanying drawings, of which Figure 1 is a front elevation of ourdevice as attached to a lock 5 Fig. 2, a similar view with a portion ofthe inclosing-plate broken away, showing the interior construction; Fig.3, a perspective view of the key-shank properly notched, and Fig. 4 aperspective view of one of the catchlevers.

Our invention relates to a device for rendering locks burglar-proof, bymaking it impossible either to pick them or turn the key with anyinstrument whatever from the outside; and our object is to accomplishthis by means of a cheap and simple cont-riva-nce, which may easily beadjusted to any look without injuring or impairing the same. i To thisend our invention consists in employing two levers working upon separatepivots, attaching them to a plate or to the lock, the said levers havingtheir lower ends bent inward, and beingprovided with aspring, tending tobring the said bent ends toward each other, whereby, when the device isattached to the lock in proper position, the said bent endsenternotchesformed in the key-shank whenever the latter is so turned asto lock the door, all as hereinafter more fully set forth.

Referring to the drawings, AA are the pair of .nippin g-levers, havingtheir fulcrums at p, where they are pivoted to a plate, B, and havingtheir upper ends broadened into plates r, and their lower ends, 8, bentinward, as shown.

A spring, 0, tends to spread the upper ends apart and bring the ends 8toward each other.

The plate B is attached, by means of screws or rivets, to the look D, insuch position that the ends 8 of the levers are brought in line with thecenter of the circular aperture, forming the upper part of the keyhole,and which receives the shank of the key.

The plate B may be cut away, as represented in Fig. 1, in order that itshall not obstruct the key-hole.

The shank E is provided with two notches or recesses, t, opposite eachother, and in such position that when the key is inserted they will bevertical with relation to each other, or in line with the length of thekey-hole, and equally distant with the ends 8 of the levers from theentrance to the key-hole.

The operation ofour device is as follows: The key having been inserted,(to permit which it is necessary, of course, to press the upper ends ofthe levers together,) the ends 8 rest against the unrecessed sides ofthe key, thus allowing the latter to be easily turned. When, however,the key is so turned as to lock the door, as represented by the dottedlines in Fig. 2, the notches are brought around so as to engage with theends 8, when the latter im mediately fly into them by the force of thespring O, as shown in Fig. 2, thus holding the key firmly, and renderingit impossible to turn it back without first pinching the upper ends ofthe levers, which are accessible only from the inside of the room. Notonly does this prevent the turning of the key by means of nippers, andthus unlocking the door with it, but it also serves to hold the key as afirm barrier, beyond which no picking-instrument can possibly be forced.

The ends 8 enter the notches also when the key is turned to acorresponding position in the opposite direction in unlocking the door,thus rendering the key little liable to be taken out by children andlost.

'VVhile we prefer to employ the plate B, it is evident that the leversmay, if desired, be piv oted to the metal of the lock itself.

I Other forms of spring than the one shown, also, may be employedwithout a material de parture from our invention.

What we claim as new, and desire to secure by Letters Patent, is

The safety attachment for looks, consisting of the levers A, pivoted attheir fulcrums to a plate, B, and having their lower ends, 8, bentinward, as shown, to enter notches t in the key-shank, in combinationwith the spring 0, substantially as described.

DANIEL E. DOPP. LOUIS O. WALTERS.

1n presence of H. E. WOAKEY,

E. F. MERRILL.

